In order for a bowler to have the greatest advantage in his attempt to consistently score the maximum number of pins, the bowling ball is released from one or more of the middle fingers by applying pressure to ball through the bowling ball finger holes in a complex motion known to those skilled in the art as lift. Lift, as known in bowling and as shown for example in U.S. Pat. No. 4,371,163 of Shaffer, means imparting to the ball the two rotary motions of roll and spin. To achieve roll, the ball is made to rotate in a forward and downward direction relative to the horizontal axis along the direction of travel of the ball toward the pins and to achieve spin, the ball is made to rotate with a rotational component about the vertical axis of the ball, as viewed from above a ball thrown with the right hand. It is the spin that causes a desired scattering of the falling pins, increasing the chance for a strike.
As stated above, this complex motion of imparting two rotary motions of roll and spin is known to those skilled in the art as lift. Lift is produced, after the thumb has been removed from the ball, by one or more of the middle fingers applying a force to the ball at its release to rotate the ball upward, imparting the desired roll and spin. To perform this operation in the best manner requires the bowler, in releasing the ball, to consistently apply his maximum force through one or more of the bowler's middle fingers, against the interior surface of the bowling ball finger hole. In bowling, this operation is repeated from a minimum of twelve for a perfect game, to a maximum of twenty one times, depending on the bowler's success in scoring a strike or spare in the last regular frame. Multiplied by a number of games, for example in league play, there is typically three full games with a minimum of thirty six ball released to a maximum of sixty three balls released. The multiplied acts of bowling, involving lifting the ball on its release, produces multiple strains and stresses on the bowler's finger. Critical to properly lifting and releasing the bowling ball, is maintaining the best possible positioning of the middle finger or fingers against the bowling ball hole, to consistently apply the proper amount of lift to the ball. As the hard surface of the bowling ball finger hole is continually forced against the bowler's extended finger, producing stress and strain in the finger, the ability of the bowler to maintain consistent control through middle finger or fingers at the ball release, is reduced, detrimentally affecting the bowler's ability to consistently lift the ball and consistently score strikes.
In attempts to adjust the curved position of the finger, a strap was used as shown in U.S. Pat. Nos. 3,152,337 and 3,880,426. As shown therein the strap was adjustable relative to an anchor point on the wrist. However the devices as shown in these patents placed the strap in a straight line locus from the curved finger tip area to the anchor point, imposing a space between the strap and the finger and palm. The size or depth of the space was relative to the adjustment made to the position of the finger tip, the amount of tension applied to the strap, the curve produced in the finger, and the relative placement or disposition of the strap to the wrist anchor point. As a consequence, when the bowler placed his finger into the bowling ball finger hole with the finger and palm forced against the ball, the strap extending in a line from the curved finger to the wrist anchor point, was forced against the finger and palm, changing the straight line locus of the strap from the finger to the anchor point, to a curved line locus from the finger to the palm and changing the original adjustment to the strap and its force on the finger, as previously made by the bowler.